1. Field of the Invention
The invention herein pertains to an overtemperature control or protection means incorporated substantially in any type of electric flatiron to protect the soleplate from overheating in the event of failure or inability of the thermostat to open the electrical circuit.
2. Description of the Prior Art
In irons of the various types available today, such as conventional dry flatirons or irons with steam and/or spray features, a thermostat is used to open and close the circuit to the electric heater and thus control the temperature of the soleplate in accordance with selected temperatures for various fabrics to be ironed. There is always a danger, although slight, of some failure upon which the thermostat cannot open the electrical circuit with the result that the iron may overheat. Typically, irons are made with aluminum soleplates that may be polished, coated with a non-stick surface or with stainless steel but the main body of the soleplate is aluminum. The aluminum casting will become dangerously hot and soften and start to melt between 900.degree. and 1100.degree. F. Thus, it has generally been necessary to consider the maximum temperature of such irons as about 900.degree. F. Additionally, current irons use much lower melting plastic housings in place of the former metallic housings, so are subject to melting of such housings in addition to the softening or melting of the soleplate.
Prior art irons have used the equivalent of a fuse in the line in order to avoid overtemperature conditions, but this has not been satisfactory because of unreliability of the fuse and the inability of the designers to provide a device that can be mass produced with reliable repetition. A typical overtemperature protection means for use with irons, that has been successfully mass produced on a large scale, is disclosed and claimed in U.S. Pat. No. 3,665,152 of common assignment. It discloses a current and successful version of an overtemperature protection means as used in assignee's irons for numerous years. It also sets forth the necessary parameters and problems encountered in possible overheating of irons and discloses an overtemperature control to prevent melting of the soleplate. This is the best known prior art applicable to the instant invention and reference is made thereto for a complete background of the problem and solution. The present invention is an improvement on that patent and, structurally, provides an arrangement wherein the fusible soldered joint of the prior art is a non-electrical current carrying element and the joint is used instead as a hold-down for a spring blade which bridges the two terminals of the overtemperature limiter.